rake task example

gistfile1.rb

# [RAILS_ROOT]/lib/tasks/sample.rake

desc "print hello world!"        # description.
task "hello_world" do            # rake task name.
   p "hello world!"                 # print "hello world!"
end

namespace :myapp do
  desc "import data from somewhere"
  # load rails environment
  task :import_data => :environment do
  end

  desc "drop and create db task."
  task "drop_and_create" => ["db:drop", "db:create"] do
  end
end

### in your console
# show rake task
rake hello_world

rake hello_world
rake myapp:import_data

need much more clarity..